Wear-Resistant Guide Bushing of Sandvik HLX5T Rock Drill in Poland

The guide bushing in the HLX5T handles a substantially heavier shank adapter than development drifters—the T51 and GT60 shanks used in HLX5T production drilling are larger in diameter and heavier than T38/T45 development shanks, and the longer rod strings they support create higher sustained lateral loads on the bushing bore. In KGHM's Polish sublevel stoping production, the guide bushing wears through a specific mechanism that the machine's production application creates: when the drill string contacts the hole wall at depth—which happens regularly in KGHM's steeply dipping ore where the 35-meter holes tend to deflect toward the hanging wall—the lateral force from that contact is transmitted back through the string to the shank adapter and directly into the guide bushing at the drifter's front housing.

This hole-wall contact load is not predictable in magnitude or timing—it depends on geological conditions at each contact point in each hole. But over a production program of 100+ rings per month at KGHM Sieroszowice, the statistical distribution of contact loads produces a bushing wear pattern that is 60% higher than KGHM's development drifter bushing wear at the same site. The higher wear rate was identified by comparing bushing clearance measurements from HLX5T longholes versus the DD2710 development machines' guide bushings at the same 500-hour inspection interval.

Guide Bushing Wear Rate Comparison at KGHM Sieroszowice

KGHM Sieroszowice's HLX5T maintenance protocol inspects guide bushings at 300 hours—the T51 string data showed that waiting to 500 hours produced consistent clearance exceedances and premature percussion seal failures from the resulting off-axis shank loading. HOVOO supplies wear-resistant HLX5T guide bushings in the T51 and GT60 bore dimensions for Polish production drilling. References at hovooseal.com.